Kerf cutting device



NOV. 19, 1946. SIMMONS 2,411,170

KERF CUTTING DEVICE Filed April 20, 1945 2 SheetsSheet 1 NOV. 19, 1946. $|MMQN$ KERF CUTTING DEVICE Filed April 20, 1945 2 Sheets-Sheet 2 Patented Nov. 19, 1946 KERF CUTTING DEVICE Leon E. Simmons, Claremont, N. H., assignor to Joy Manufacturing Company, a corporation of Pennsylvania Application April 20, 1943, Serial No. 483,748

3 Claims.

This invention relates to kerf cutting devices and more particularly to an'improved cutter bit, bit mounting means and a chain block and strap link structure for a cutter chain of a coal cutting machine.

An object of the present invention is to provide an improved kerf cutting device. Another object is to provide an improved cutter chain for a coal cutting machine. A further object is to provide an improved bit mounting for a cutter chain. Still another object is to provide an improved cutter bit. A still further object is to provide an improved chain block having a novel socket arrangement for the bit mounting parts. Yet another object is to provide an improved chain block having relatively inclined, inwardly diverging, front and rear sockets, one for receiving a bit holder and the other for receiving a front bit clamp. Still another object is to provide an improved mounting arrangement for the holder parts of a bit mounting means. Another object is to provide a novel chain block and strap link structure for a cutter chain. A further object is to provide an improved strap link and hinge pin locking means. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there are shown for purposes of illustration three forms which the invention may assume in practice.

In these drawings:

Fig. l is a side elevational View of a cutter chain constructed in accordance with a preferred illustrative embodiment of the invention.

Fig. 2 is a cross sectional view taken substantially on line 22 of Fi 1.

Fig. 3 is a view in longitudinal vertical section taken substantially on line 3-3 of Fig. 2.

Fig. 4 is a horizontal sectional View taken substantially on line 4-4 of Fig. 3.

Fig. 5 is a side elevational view, partially in section, of the improved bit holder.

Fig. 6 is a top plan view of the bit holder shown in Fig. 5.

Fig. 7 is a perspective View of the front bit clamp.

Fig. 8 is a perspective View looking toward the front cutting face, of the improved cutter bit.

Fig. 9 is a cross sectional view taken substantially on line 89 of Fig. 8.

Fig. 10 is a fragmentary view in side elevation illustrating a portion of the strap link and hinge pin lock.

Fig. 11 is a detail sectional view taken substantially on line Hl l'of Fi 10. l

Fig. 12 is a sectional view similar to Fig. 3 illustrating another form of the invention.

Fig. 13 is a front end elevational view of the structure shown in Fig. 12.

Fig. l i is a side elevational view, partially in section, of the bit holder shown in Fig. 12.

Fig. 15 is a rear elevational view of the bit holder shown in Fig. 14.

Fig. 16 is a front elevational holder shown in Fi 14.

Fig. 17 is a side elevational View, partially in section, of the front clamp shown in Fig. 12.

Fig. 13 is a rear elevational View of the front clamp.

view of the bit Fig. 19 is a front elevational view of the cutter bit shown in Fig. 12.

Fig. 20 is a cross sectional view taken on line 2920 of Fig. 19.

Fig, 21 is a sectional View similar to Figs. 3 and 12, illustrating still another form of the invention.

Fig. 22 is a perspective view of the bit holder shown in Fig. 21.

Fig. 23 is a perspective view of the front clamp shown in Fig. 21.

Fig. 24 is a perspective View of the cutter bit shown in Fig. 21.

In the illustrative embodiment of the invention shown in Figs. 1 to 11 inclusive, there is a cutter chain comprising a chain block I connected by hinge pins 2 to strap links 3. The strap links have lateral gibs i received in the guideways 5 of a cutter bar 5 as shown in Fig. 2. The chain block has lateral ledges l at its opposite sides which overlie the outer sides of the strap links 3 in the manner shown in Fig. 2, to hold the strap links against lateral release in a manner to be later explained The hinge pins 2 extend between guide strips 8 suitably fixed to the outer bar plates ii of the cutter bar. The hinge pins are locked against rotation relative to the chain block by keys l9 seated in longitudinal. key slots formed respectively in thepins and block. The keys it are arranged between, and at their ends abut, the inner surfaces of the strap links. When the strap links are turned through substantially into the position shown in Fig. 10, slots II in the links are brought into registry with the keys Hl so that the latter may be driven out, thereby to enable removal of the hinge pins. When the hinge pins are removed the strap links may be readily moved out of their interlocking relation with the ledges l on the chain block. Of course, the chain must be moved out of the guideways of the cutter bar, before removal of the pins and their keys.

The chain block has a lateral lug l2 formed with relatively inclined, inwardly diverging front and rear sockets in the form of bores 13 and [4 which converge near the outer surface of the block lug, the point of juncture of the bores being indicated at 15. .These bores are circular in cross section and at their inner ends are spaced a substantial distance apart longitudinally of the chain block as shown in Fig. 3. A bit holder it; has a head I? adapted to rest at E8 on the outer surface of the block lug, and integral with the holder head is a cylindric shank l9 adapted for reception in and fitting the rear block bore it. The forward side of the holder head I? is vertically slotted at 2@. A cutter bit, generally designated 2|, is shown as of the reversible, double pointed type having a front plane cutting face 22 of generally elliptical shape terminating in cutting points 23, 23 at the opposite ends of the bit body. The bit body is preferably of generally T-shape in cross section, as shown in Fig. 9, throughout a substantial portion of its length, and the leg of the T is formed by a narrow flange 2d at the back of the bit, and the rear side of the bit body is arcuatel formed at 25. The flange at the back of the bit is received in the holder head slot 20, and the front cutting face of the bit rests against an inclined rearwardly facing surface 26 formed at the bottom of vertical groove 2! on an adjustable front clamp 28. This clamp has a cylindric shank portion adapted for reception and fitting the front block bore 13. The inner inactive cutting portion of the cutter bit projects into the rear lug bore M in the manner shown. A set screw 36 is threaded within aninwardly inclined opening 3! in the front part of the block ing in advance of the front bore l3, and this screw has a tapered or conically shaped inner portion 32 engaging an inclined bottom surface 33 at the inner end of the front clamp shank. When the set screw 38 is tightened, the tapered portion thereof engages the inclined clamp surface 33 for moving the clamp outwardly and rearwardly in the front lug bore into firm clamping engagement with the front face 22 of the cutter bit to hold the latter against the holder. When the front clamp is in bit clamping position, it projects in part into the rear lug bore M.

In the embodiment shown in Figs. 12 to 20 ininclined, inwardly diverging lug bores 35 and 35 in the block have an abutment surface 31 extending therebetween near the juncture of the bores as shown in Fig. 12. A bit holder 38 has a head 39 and a cylindric shank t6, and the head has an inwardly located abutment M at the forward side of the holder shank. In this instance, the holder head does not rest on the exterior of the block lug, and the head surface 4! seats against the abutment surface 3? intermediate the lug bores. A cutter bit, generally designated 42, of generally arcuate shape in side elevation, has relatively inclined cutting portions d3, d3 terminating in cutting points M at the opposite extremities of the bit body. The bit body is substantially T-shape in cross section as shown in Fig. 20, and the leg of the T is provided by anarrow flange at the back of the bit. The side ledges 6, 45 at the head of the T arecurved inwardly at 41 toward the cutinthe forward side of the holder head 39, Re-

ceived in the front lug bore 35 is a cylindric shank 51 of a front bit clamp 52, and a rearwardly facing surface 53 on the clamp is shaped to conform with the curved central portion 54 of the forward side of the bit as shown in Fig. 12. The rear side of the shank 5| of the front clamp is vertically grooved at 55 to receive the inner inactive cutting portion of the cutter bit. When the cutter bit is held in cutting position between the holder and the front clamp, the inactive cutting portion thereof extends into the front bore 35 of the block .lug. A set screw 56 is threaded within an inwardly inclined opening 5? in the block lug in advance of the front bore 35, and this screw has a conical or tapered end portion 58 engaging a bottom inclined surface 59 at the inner end of the clamp shank. When the set screw 56 is tightened, the tapered portion 58 thereof acts on the inclined clamp surface 59 to move the front clamp outwardly and rearwardly in the front lug bore rmly to clamp the cutter bit against the holder head.

In the embodiment shown in Figs. 21 to 24 inclusive, the block and strap link structure is similar to that of the preferred embodiment. In this instance, a chainblock lug E!) has relatively inclined, inwardly diverging bores 6i and 52. Re ceived in the rear lug bore is a cylindric shank 63 of a holder $4, the latter having a recess 65 opening through its forward side and an inner abutment surface 66 at the bottom of the recess. A cutter bit, generallydesignated 6?, has a body of generally trapezoidal shape in side elevation and preferablyof diamond shape in cross section. The .bit body is formed with relatively inclined, inwardly diverging cutting faces @ii, 58 terminating in cutting points 69 at the opposite extremities of the bit at the same side of the bit body. The inner portion of the cutter bit is received in the holder socket 55 with the inner inactive cutting face of the bit resting against the abutment surface 66. The inner inactive end of the cutter bit projects within the rear lug bore 62 in the manner shown. A cylindric front clamp it is received in the front lug bore of and has a rearwardly facing abutment surface 72 with which the inner portion of the active cutting face of the bit engages. A set screw 13 is threaded Within a longitudinal opening 14 in the block lug at the forward side of the front lug bore .65, this screw has a rounded end 5'5 engaging an inclined inner surface '56 on the front clamp iii. When the set screw 73 is tightened, the front clamp is moved outwardly and rearwardly in the front lug bore firmly to clamp the cutter bit in the holder socket.

In the several forms of the invention above described the cutter bit, when one cutting point becomes dull, may be removed from the holder simply by loosening the front clamp and turned end for end to present, upon reinsertion in the holder, a sharp cutting point to the Work, Also the block lug is symmetrically formed and is provided With a rear set screw opening so that the parts may be reversed on the block to hold the.

' metrical arrangement, providing for reversible chain, is unnecessaryfor the obtaining of many of the advantages of my invention from certain of its aspects. The holder and clamp structure .and the novel arrangement of'the block lug bores, afford an extremely simple bit mounting for firmly securing a cutter bit in cut-ting position on the chain block. This structure is not only simple in design, but it is also rugged and durable and extremely compact. The novel strap link and hinge pin lock of the preferred embodiment of the invention provides an effective means for holding the hinge pins against rotation relative to the block, thereby concentrating wear on the relatively inexpensive strap links. Also the strap links are efiectually interlocked with the chain block. Other advantages of the invention will be clearly apparent to those skilled in the art.

While there are in this application specifically described three forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is: v

1. In a cutter chain, a chain block having a lateral lug, said lug having relatively inclined, front and rear bores arranged with their axes in a common plane and diverging downwardly at an acute angle with each other, said bores being so arranged that they merge together at their outer portions and there being provided a transverse abutment surface, at an angle to the adjacent walls of each of said bores, between said bores near their juncture, bit mounting means associated with said block including relatively adjustable supporting and holding elements received in said bores respectively, and meansv for effecting relative adjustment between said elements and for securing said elements in position in said bores, one of said elements having an inner abutment surface resting against said transverse abutment surface when said elements are secured in bit holding position.

2. In a cutter chain, a chain block having a lateral lug, said lug having relatively inclined, front and rear bores arranged with their axes in a common plane and diverging downwardly at an acute angle with each other, said bores being symmetrically arranged with respect to said block and having their axes'lying in the central longitudinal median plane of said block, bit mounting means associated with said block including relatively adjustable bit supporting and holding elements received in said bores respectively, said supporting and holding means being interchangeable in said bores whereby a cutter bit may be mounted selectively in reverse positions to cut in either of opposite directions, and means for efiecting relative adjustment between said elements and for securing said elements in position in said bores.

3. In a cutter chain, a chain block having a lateral lug, said lug having relatively inclined, front and rear bores arranged with their axes in a common plane and diverging downwardly at an acute angle with each other, said bores. being so arranged that they merge together at their outer portions and there being provided a transverse abutment surface, at an angle to the adjacent walls of each of said bores, between said bores near their juncture, bit mounting means associated with said block including relatively adjustable supporting and holding elements each receivable in either one of said bores, a cutter bit held in cutting position between said supporting and holding elements in said bores and facing in one direction or the other dependent upon the assembly of said elements in said bores and having its inner end projecting inwardly to a position in which at least the extremity of such end lies solely in one of said bores, and means for effecting relative adjustment between said elements to effect bit clamping and the securing of said elements in position in said bores, one of said elements having an inner abutment surface resting against said transverse abutment surface when said elements are secured in bit holding position in either assembled position thereof in said bores.

LEON E. SIMMONS. 

